The present invention relates to electronic dot matrix impact printers and more particularly to novel apparatus and circuitry for achieving two-color printing therein.
Conventional electronic dot-matrix impact printers use a print head containing a plurality of solenoid-driven print wires to selectively urge each print wire end against an inked ribbon positioned above the surface of a paper document and the like, to print a row of dots thereon. The print head is mounted on a carriage movable across the document, while selected combinations of print wires are driven against the ribbon and paper to form a group of dot columns which collectively represent a line of dot-matrix characters. Typically, a dot-matrix impact printer prints in only one color, generally black. In certain applications it is desirable to be able to either print each line in one of two colors, such as black and red, or print lines of intermixed characters of first and second colors.